ANCHORAGE - When woodworker Jim Crum and his wife moved to a home with a swamp out back, they were attacked by one of Alaska's most bloodthirsty hunters - mosquitoes.
Instead of being eaten alive, Crum got busy building a 56-room birdhouse for purple martins. He read that the largest member of the swallow family can eat up to 5,000 mosquitoes a day.
"I said, 'You know, 56 times 5,000, we can wipe the town out,' " Crum said, reflecting on the inspiration for one of thousands of birdhouses he's built since the mid-1980s.
The purple martin mansion was a flop. While beautifully crafted, it failed to attract even one bird because purple martins don't nest closer than Vancouver, British Columbia. Squirrels quickly moved in and have been enjoying the mansion ever since.
Crum, a 58-year-old retired civil engineer, has learned a lot since then about how to make the perfect home for mosquito-munching birds. Now he can easily turn out a couple of dozen birdhouses at a stretch from a workshop in the garage of his Anchorage home.
Crum builds homes for tree swallows and violet-green swallows, two types of birds that love mosquitoes and nest in Alaska. The birds begin nesting in mid-May, about the same time the largest of the Alaska mosquitoes the slow-moving snow mosquito begins biting. Those insects are followed by swarms of smaller, nastier cousins.
A couple of nesting swallows can make relaxing on the back deck bearable, Crum said.
The average swallow consumes about 6,000 insects a day, according to the Rainier Audubon Society in Washington. While tending young, the parent birds make about 350 trips, bringing as many as 8,000 mosquitoes back to the nest.
"They are so aerobatic," said A.J. Fisher, Rainier's nest box coordinator. "They go back and forth and back and forth into those nest boxes all day long. ... We can sit on our deck and aren't bothered by mosquitoes."
The society sells between 30 and 50 nesting boxes a year. A few years ago, the city of Renton bought 100 boxes instead of spraying pesticides in a heavily-infested neighborhood near a swamp,
"The swallows took care of the mosquitoes," Fisher said.
Crum first finds scrap lumber neighbors donate old fencing because purchased materials kill the slim profit margin in homemade birdhouses. He next sets his sights on a good design, perhaps something he's spotted in a book, and modifies it to his liking.
"It is interesting to make something and see how it works," Crum said.
Tree swallows and violet-green swallows like a nesting box that measures 6 inches on all sides with a 138-inch hole. The roof is caulked to keep baby birds dry. A small cut in the wood near the top provides ventilation. And the bottom is secured with screws that can be removed for easy cleaning.
That's all the birds need, Crum said. Any other adornments are to attract customers.
"The birds don't care. All the birds want is a tree with a knot hole and a little cavity," he said.
Crum, former president of Alaska Creative Woodworkers Association, makes his own cedar shakes for the top, no knots and thinly sliced to give the birdhouse a classy look. He puts a strip of cedar flashing on the top. He bevels the edges of the box.
Leaning over his workbench, Crum dry-brushes the trim with gray paint to give his birdhouses a weathered look. That will attract what he calls the "Gucci traffic."
"It ages it," he said. "This is purely for the tourists."